y is odd, is z odd?

This topic has expert replies
Source: — Data Sufficiency |

User avatar
MBA Admissions Consultant
Posts: 2279
Joined: Fri Nov 11, 2011 7:51 am
Location: New York
Thanked: 660 times
Followed by:266 members
GMAT Score:770

by Jim@StratusPrep » Fri Mar 29, 2013 7:25 am
1) The only way the product of 3 numbers can be odd is if all are odd. Z must be odd SUFFICIENT
2) We have no idea if Z or X is odd or even. INSUFFICIENT


A
GMAT Answers provides a world class adaptive learning platform.
-- Push button course navigation to simplify planning
-- Daily assignments to fit your exam timeline
-- Organized review that is tailored based on your abiility
-- 1,000s of unique GMAT questions
-- 100s of handwritten 'digital flip books' for OG questions
-- 100% Free Trial and less than $20 per month after.
-- Free GMAT Quantitative Review

Image

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Fri Mar 29, 2013 7:50 am
As Jim has stated, the answer is A. However, I should point out that the answer is A only if we first restrict x, y and z to integer values.

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image

User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Fri Mar 29, 2013 2:41 pm
himu wrote:If y is odd, is z odd?

xyz = odd
yz = x
If the problem is not restricted to integers:

All of the conditions are satisfied if x=1, y=1, and z=1.
In this case, z is odd.

All of the conditions are satisfied if x=1, y=3, and z=1/3.
In this case, z is not odd.

The correct answer is E.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3

Master | Next Rank: 500 Posts
Posts: 341
Joined: Sun Mar 25, 2012 6:59 pm
Thanked: 17 times
Followed by:4 members
GMAT Score:720

by ice_rush » Sat Mar 30, 2013 11:59 am
I think the answer should be E -- Why are we assuming the numbers are integers? Together the two statements tell us that X is odd - don't know anything about Z.

User avatar
Master | Next Rank: 500 Posts
Posts: 345
Joined: Sun Dec 21, 2008 10:57 pm
Thanked: 6 times
Followed by:3 members

by himu » Sat Mar 30, 2013 9:36 pm
Yes Thanks ice_rush,GMATGuruNY,Brent@GMATPrepNow & Jim@StratusPrep,

The OA is E.

User avatar
MBA Admissions Consultant
Posts: 2279
Joined: Fri Nov 11, 2011 7:51 am
Location: New York
Thanked: 660 times
Followed by:266 members
GMAT Score:770

by Jim@StratusPrep » Mon Apr 01, 2013 7:09 am
Yes.... lesson in reading to quickly there.
GMAT Answers provides a world class adaptive learning platform.
-- Push button course navigation to simplify planning
-- Daily assignments to fit your exam timeline
-- Organized review that is tailored based on your abiility
-- 1,000s of unique GMAT questions
-- 100s of handwritten 'digital flip books' for OG questions
-- 100% Free Trial and less than $20 per month after.
-- Free GMAT Quantitative Review

Image